There were 45 homicides in Toronto last year. It’s a grim group: a 28-year-old man was gunned down at a family barbecue; a 21-year-old mother of a two-year-old was strangled by her estranged husband; a 35-year-old police officer died when he was struck by a stolen snowplow. But, to criminologists at least, 45 is good news. That’s 16 fewer victims than 2010, and a precipitous fall from the all-time high of 89 in 1991. Overall crime rates have dropped by almost half since 1992, despite the fact that the city keeps growing by an average of 34,000 people a year.

Crime is vanishing in cities across North America, though the decrease is most dramatic in large cities like Toronto. The way we’re policed is as much a factor as demographics and social engineering. Since Bill Blair took over as chief in 2009, he has touted the benefits of community policing. The methods—200 desk cops reassigned to street patrols, more officers on bikes, meet-and-greets with residents, police stationed in schools and the determined recruitment of women and minorities—sound like small gestures, but the result is often a shared intolerance for lawbreakers and a profound shift in how a community perceives the force. Criminologists have discovered that the crime drop has had little to do with locking criminals up in jail and everything to do with interrupting a cycle of crime. Criminal acts, it turns out, are committed out of convenience, and fewer get committed if you make crime inconvenient by placing more cops on the sidewalk.